Well she was shot in the head so unless she tripped and fell on a bullet, it wasn't an accident.

Castle: The fact that you even think that breaks my heart. I would walk into a tornado for you, Kate.
Beckett: And I would die if I lost you.

Castle: Kate, I have never given up hope, not since the day we met and that will never change until you tell me it should.
Beckett: Then don't change, ever.

Castle: They've been through way too much together to give up on what they have.
Beckett: You're a wise man Castle, with a big heart and you're rather good looking too.
Castle: You might want to pace yourself with the flattery. You've got a whole dinner to get through.

Beckett: Martha, we're not getting a divorce.
Martha: Well, call me old fashioned but don't married couples live together?

Beckett: It's complicated.
Martha: So were his last two divorces.

Beckett: I didn't do this to hurt you, I did it to protect you.
Castle: Then why am I so angry?

Castle: Do you have any idea how worried I was?
Beckett: Yeah, I do. I was gone for 36 hours. A year ago you were gone for eight weeks.

Beckett: I mean, what did you want me to do?
Castle: Tell me the truth.

Castle, just shut up and kiss me.

Look on the bright side, chicks dig scars.

Worst thing I thought I was going to be facing was working without Castle, and then you called.

Castle Quotes

I don't get it. He's into you and your determined not to give into these feelings that you clearly have for him. So he fantasizes about you through his writing. It is literally verbal masturbation.

Natalie

I can't tell you how many times I've had dreams of being on this very ship.

Beckett